I have an AVI file that is recorded with a screencap tool. The file plays perfectly in both VLC and Windows Media Player, but when I open it in VirtualDubMod, the video is skewed to the left - and also it's in black and white:
The odd thing is that when I play the video in VirtualDobMod, it plays fine (and in colour) - but when I trim the video and save it (in Full Processing Mode), the output file is skewed
Any idea what is going on? I haven't applied any filters to the video stream.
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General Complete name : Arven 1-5.avi Format : AVI Format/Info : Audio Video Interleave Format profile : OpenDML File size : 1.19 GiB Duration : 1h 3mn Overall bit rate : 2 692 Kbps Writing application : Lavf52.23.1 Video ID : 0 Format : MPEG-4 Visual Codec ID : MP42 Codec ID/Info : Microsoft MPEG-4 v2 (pre-standard) Codec ID/Hint : Microsoft Duration : 1h 3mn Bit rate : 2 584 Kbps Width : 938 pixels Height : 524 pixels Display aspect ratio : 16:9 Frame rate : 15.000 fps Compression mode : Lossy Bits/(Pixel*Frame) : 0.350 Stream size : 1.14 GiB (96%) Audio ID : 1 Format : MPEG Audio Format version : Version 1 Format profile : Layer 3 Codec ID : 55 Codec ID/Hint : MP3 Duration : 1h 3mn Bit rate mode : Constant Bit rate : 96.0 Kbps Channel(s) : 1 channel Sampling rate : 44.1 KHz Compression mode : Lossy Stream size : 43.5 MiB (4%) Alignment : Aligned on interleaves Interleave, duration : 26 ms (0.39 video frame)
If the dimensions of your image are accurate (938x524), I'd guess it's a mod2 thing. It's something to do with a Windows API I don't really understand, but the upshot of it is, some programs don't like mod2 YUV video.
Traditionally all video was mod16 (the width and height are divisible by 16). These days it doesn't matter much, but mod4 widths are still safer. The height can be mod2. Well at least for h264. For Xvid encoding it might still be safer to at least stick to a mod8 width and height, just for hardware player compatibility.
If you're just wanting to re-encode while trimming it, the easiest way might be to use a different program. Handbrake would be nice and easy to use, but it'll only encode with the x264 encoder. MeGUI can output Xvid AVI but it's harder to use. If I'm correct, lots of programs should be able to open and re-encode it, just not VirtualDub(Mod). Although..... if you happen to have ffdshow installed and it happens to be doing the decoding, you should be able to use it's crop or resize filter to resize the video to a mod4 width as it's being decoded.
Last edited by hello_hello; 23rd Jan 2014 at 07:42.
Yes, the VFW MP42 decoder doesn't like the mod2 frame width. Try using a different MP42 decoder. Sometimes you can patch the AVI header to work around this but you have to know what you're doing.